The present invention pertains generally to fabrication techniques to be used for fabricating micro refractive, such as Fresnel, optics and compound optic comprising two or optical elements for short wavelength radiation. One application is the fabrication of the (AFO) described in U.S. patent application Ser. No. 10/134,026, which is incorporated herein by this reference in its entirety.
The Achromatic Fresnel Optic (AFO) is a multi, such as two, element compound optic that is comprised of a diffractive Fresnel zone plate and a one or more refractive Fresnel lenses. The optic is described in U.S. patent application Ser. No. 10/134,026 (U.S. Pat. Appl. Publ. No. US 2005/0168820 A1), which is incorporated herein by this reference in its entirety. Further uses for the optic are described in U.S. patent application Ser. No. 10/683,872 filed on Oct. 10, 2003, by Wenbing Yun and Yuxin Wang (U.S. Pat. Appl. Publ. No. US 2004/0165165 A1), which is incorporated herein by this reference in its entirety.
Generally, the AFO is used for imaging short wavelength radiation including extreme ultraviolet (EUV) and x-ray radiation with wavelengths in the range of 0.02 nanometers (nm) to 20 μm. The diffractive element(s) is the primary focusing element, and the refractive element typically provides no or very little net focusing effect. It serves to correct the chromatic aberration of the zone plate.